Glaciers in the Rocky Mountains and other areas of British Columbia could be all but wiped out within a century due to climate change, says a newly published study suggesting the impact of rising temperatures could be worse than previously thought, choking salmon-spawning streams and drying up ski resorts.
The study, published Monday in the journal Nature Geoscience, used 3-D simulations to predict the potential impact of glacier melt over the next 100 years.
"People driving into Banff or Jasper parks will be hard pressed to see glaciers in the landscape by the time this is played out," said study co-author Garry Clarke, a professor emeritus with the University of British Columbia.
The study allowed researchers to hold a magnifying glass to specific areas in Western Canada to predict local impacts of climate change.
The researchers anticipate a near total loss of glacial ice in areas of the Rocky Mountains and in B.C.'s southeastern Columbia Mountains by the year 2100.
But the mountains along B.C.'s southern coast may fare better than previously expected, mostly sparing the visually stunning Mount Garibaldi, north of Squamish, B.C., and ice caps in B.C.'s northwest, close to the Alaska and Yukon borders, should also survive.
Researchers spent nearly a decade creating their simulation, resulting in high-resolution representations of the glacial degradation in B.C. and Alberta over the years.
While the entire region currently sustains 3,000 cubic kilometres of ice, that's projected to degrade between 60 to 80 per cent using the simulation, which charts four possible courses based on standard climate-change scenarios. The study projects the maximum rate of ice volume retreat to occur between 2020 and 2040.
Earlier forecasts using less sophisticated calculus predicted the glacial mass loss would be lower.
"This is not a trivial amount," Prof. Clarke said. "This is in the world league in terms of how many glaciers we have in our mountains and what the losses will be."
He said the big unknown is human behaviour – how rapidly the glaciers permanently flow into the ocean depends on carbon dioxide and greenhouse gas additions to the atmosphere.
It's a "one-way trip" if melt rates worsen or even continue along the current trajectory, he said. But the simulator also showed unexpectedly positive outcomes where some glaciers could outlast the prediction if climate change stabilizes, he added.
"I thought that we might not even have a possibility of a good result, even if we behaved really nicely," he said. "But this suggests there is a reward for good behaviour."
Digital pictures of the models at increments from 2010 to 2100 look exactly as if photographed from satellites, but are truer to life because they simulate the physics of ice flow, Prof. Clarke said.
The novel simulator is more sophisticated than other calculators, using technological prowess similar to flight simulation or car racing programs, he said.
"You've got the physics that describes what's going on. You try to put as much as you can in there. And if you've done a good job, it resembles the system you're trying to emulate," Prof. Clarke said.
The team included factors such as the strength of the Earth's gravity field and the melting temperature of ice, and it also accounted for precipitation falling as snow or rain depending on elevation.
But Prof. Clarke noted that in some ways, the melt isn't as dire in Canada because the glacial water doesn't sustain huge populations.
He's hoping the simulator will be adopted by glacier experts in Asia and South America, where people's livelihoods depend on access to water.